Mr. Tambourine Man
Interesting story about this one. Bob Dylan, who composed this song, originally wanted to record it as part of his last fully acoustic album, Another Side Of Bob Dylan, and in fact did record a version with Ramblin' Jack Elliott. However, the take was not used for that album. The Byrds somehow had acquired a copy of this recording and thus were able to release their own version a mere two weeks after Dylan included a newer recording on his Bringing It All Back Home LP.
So here we have yet another instance of a cover version, done in a different style, becoming more popular than the original, and giving birth to a new subgenre of music - this time, folk-rock, one of several musical styles that The Byrds were instrumental in originating, the others including raga rock (Eight Miles High) and country-rock (Sweetheart Of The Rodeo). The Byrds' use of harmonies and jangly 12-string transformed an acoustic-and-harmonica-driven folk song into an instant pop classic, and ushered in the era of psychedelia. The song hit the number one spot on both sides of the Atlantic, and it is listed at #79 on Rolling Stone's 500 Greatest Songs Of All Time (Dylan's version is at #106).